fix conversation delete

Signed-off-by: Stephanie <yangcao@redhat.com>

Author: yangcao77

src/app/endpoints/conversations.py

@@ -248,6 +248,15 @@ async def get_conversation_endpoint_handler(
         client = AsyncLlamaStackClientHolder().get_client()
 
         agent_sessions = (await client.agents.session.list(agent_id=agent_id)).data
+        if not agent_sessions:
+            logger.error("No sessions found for conversation %s", conversation_id)
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail={
+                    "response": "Conversation not found",
+                    "cause": f"Conversation {conversation_id} could not be deleted: no sessions found",
+                },
+            )
         session_id = str(agent_sessions[0].get("session_id"))
 
         session_response = await client.agents.session.retrieve(
@@ -283,6 +292,8 @@ async def get_conversation_endpoint_handler(
                 "cause": f"Conversation {conversation_id} could not be retrieved: {str(e)}",
             },
         ) from e
+    except HTTPException:
+        raise
     except Exception as e:
         # Handle case where session doesn't exist or other errors
         logger.exception("Error retrieving conversation %s: %s", conversation_id, e)
@@ -339,11 +350,22 @@ async def delete_conversation_endpoint_handler(
     try:
         # Get Llama Stack client
         client = AsyncLlamaStackClientHolder().get_client()
-        # Delete session using the conversation_id as session_id
-        # In this implementation, conversation_id and session_id are the same
-        await client.agents.session.delete(
-            agent_id=agent_id, session_id=conversation_id
-        )
+
+        agent_sessions = (await client.agents.session.list(agent_id=agent_id)).data
+
+        if not agent_sessions:
+            logger.error("No sessions found for conversation %s", conversation_id)
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail={
+                    "response": "Conversation not found",
+                    "cause": f"Conversation {conversation_id} could not be deleted: no sessions found",
+                },
+            )
+
+        session_id = str(agent_sessions[0].get("session_id"))
+
+        await client.agents.session.delete(agent_id=agent_id, session_id=session_id)
 
         logger.info("Successfully deleted conversation %s", conversation_id)
 
@@ -371,6 +393,8 @@ async def delete_conversation_endpoint_handler(
                 "cause": f"Conversation {conversation_id} could not be deleted: {str(e)}",
             },
         ) from e
+    except HTTPException:
+        raise
     except Exception as e:
         # Handle case where session doesn't exist or other errors
         logger.exception("Error deleting conversation %s: %s", conversation_id, e)

src/utils/endpoints.py

@@ -109,6 +109,15 @@ async def get_agent(
         await client.agents.delete(agent_id=orphan_agent_id)
         sessions_response = await client.agents.session.list(agent_id=conversation_id)
         logger.info("session response: %s", sessions_response)
+        if not sessions_response or not sessions_response.data:
+            logger.error("No sessions found for conversation %s", conversation_id)
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND,
+                detail={
+                    "response": "Conversation not found",
+                    "cause": f"Conversation {conversation_id} could not be retrieved.",
+                },
+            )
         session_id = str(sessions_response.data[0]["session_id"])
     else:
         conversation_id = agent.agent_id